Yes, they are worth face value (one cent each). Please check your pocket change - only cents from Denver and San Francisco carry mint marks. Cents struck at Philadelphia and West Point do not have mint marks so they are indistinguishable from one another.
A 1941 penny without a mintmark means it was minted in Philidelphia.
A Lincoln cent without a mintmark was struck at the Philadelphia Mint. The Mint does not use "P" mintmarks on penny's.
Low grade coins retail at 25 cents to $1.25, better grade can be $3.00-$5.00
If it is a proof then it will have the mintmark "S". If your coin doesn't have the mintmark "S" then it is just a normal coin.
There is no mintmark on the 1921 British Penny, they were all minted at the Royal Mint London.
If there is a mintmark at all, it will be a very small "H" to the left of the date in the exergue. The "H" indicates it was minted at Heaton in Birmingham. All 1912 Pennies without a mintmark were minted at the Royal Mint.
SIMPLE ANSWER: No US coin dated 1965, 1966 or 1967 will have a mintmark, it's just a penny.
A mintmark is a small identification mark used to tell which mint it was made in.
underneath the year
It will have a S mintmark.
An Australian Penny or Halfpenny with a "Y." (PENNY.) mintmark indicates that the coin was minted at the Perth Mint. An Australian Penny or Halfpenny with a "I" mintmark indicates that the coin was minted at either the Calcutta or Bombay Mints in India.
Philadelphia. Cents (pennies) from the Philadelphia mint have never carried a mintmark.